// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "cc/tiles/picture_layer_tiling.h"

#include <stddef.h>

#include <limits>
#include <set>

#include "base/bind.h"
#include "base/macros.h"
#include "base/memory/ptr_util.h"
#include "cc/base/math_util.h"
#include "cc/test/fake_output_surface.h"
#include "cc/test/fake_output_surface_client.h"
#include "cc/test/fake_picture_layer_tiling_client.h"
#include "cc/test/fake_raster_source.h"
#include "cc/test/test_context_provider.h"
#include "cc/tiles/picture_layer_tiling_set.h"
#include "cc/trees/layer_tree_settings.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "ui/gfx/geometry/quad_f.h"
#include "ui/gfx/geometry/rect_conversions.h"
#include "ui/gfx/geometry/size_conversions.h"

namespace cc {
namespace {

    static gfx::Rect ViewportInLayerSpace(
        const gfx::Transform& transform,
        const gfx::Size& device_viewport)
    {

        gfx::Transform inverse;
        if (!transform.GetInverse(&inverse))
            return gfx::Rect();

        return MathUtil::ProjectEnclosingClippedRect(inverse,
            gfx::Rect(device_viewport));
    }

    class TestablePictureLayerTiling : public PictureLayerTiling {
    public:
        using PictureLayerTiling::SetLiveTilesRect;
        using PictureLayerTiling::TileAt;

        static std::unique_ptr<TestablePictureLayerTiling> Create(
            WhichTree tree,
            float contents_scale,
            scoped_refptr<RasterSource> raster_source,
            PictureLayerTilingClient* client,
            const LayerTreeSettings& settings)
        {
            return base::WrapUnique(new TestablePictureLayerTiling(
                tree, contents_scale, raster_source, client,
                settings.tiling_interest_area_padding,
                settings.skewport_target_time_in_seconds,
                settings.skewport_extrapolation_limit_in_screen_pixels,
                312.f, /* min_preraster_distance */
                settings.max_preraster_distance_in_screen_pixels));
        }

        gfx::Rect live_tiles_rect() const { return live_tiles_rect_; }
        PriorityRectType visible_rect_type() const
        {
            return PriorityRectType::VISIBLE_RECT;
        }

        using PictureLayerTiling::ComputePriorityRectTypeForTile;
        using PictureLayerTiling::RemoveTileAt;
        using PictureLayerTiling::RemoveTilesInRegion;

    protected:
        TestablePictureLayerTiling(WhichTree tree,
            float contents_scale,
            scoped_refptr<RasterSource> raster_source,
            PictureLayerTilingClient* client,
            size_t tiling_interest_area_padding,
            float skewport_target_time,
            int skewport_extrapolation_limit,
            float min_preraster_distance,
            float max_preraster_distance)
            : PictureLayerTiling(tree,
                contents_scale,
                raster_source,
                client,
                min_preraster_distance,
                max_preraster_distance)
        {
        }
    };

    class PictureLayerTilingIteratorTest : public testing::Test {
    public:
        PictureLayerTilingIteratorTest() { }
        ~PictureLayerTilingIteratorTest() override { }

        void Initialize(const gfx::Size& tile_size,
            float contents_scale,
            const gfx::Size& layer_bounds)
        {
            client_.SetTileSize(tile_size);
            scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(layer_bounds);
            tiling_ = TestablePictureLayerTiling::Create(PENDING_TREE, contents_scale,
                raster_source, &client_,
                LayerTreeSettings());
            tiling_->set_resolution(HIGH_RESOLUTION);
        }

        void InitializeActive(const gfx::Size& tile_size,
            float contents_scale,
            const gfx::Size& layer_bounds)
        {
            client_.SetTileSize(tile_size);
            scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(layer_bounds);
            tiling_ = TestablePictureLayerTiling::Create(ACTIVE_TREE, contents_scale,
                raster_source, &client_,
                LayerTreeSettings());
            tiling_->set_resolution(HIGH_RESOLUTION);
        }

        void SetLiveRectAndVerifyTiles(const gfx::Rect& live_tiles_rect)
        {
            tiling_->SetLiveTilesRect(live_tiles_rect);

            std::vector<Tile*> tiles = tiling_->AllTilesForTesting();
            for (std::vector<Tile*>::iterator iter = tiles.begin();
                 iter != tiles.end();
                 ++iter) {
                EXPECT_TRUE(live_tiles_rect.Intersects((*iter)->content_rect()));
            }
        }

        void VerifyTilesExactlyCoverRect(
            float rect_scale,
            const gfx::Rect& request_rect,
            const gfx::Rect& expect_rect)
        {
            EXPECT_TRUE(request_rect.Contains(expect_rect));

            // Iterators are not valid if the destination scale is smaller than the
            // tiling scale. This is because coverage computation is done in integer
            // grids in the dest space, and the overlap between tiles may not guarantee
            // to enclose an integer grid line to round to if scaled down.
            ASSERT_GE(rect_scale, tiling_->contents_scale());

            Region remaining = expect_rect;
            for (PictureLayerTiling::CoverageIterator
                     iter(tiling_.get(), rect_scale, request_rect);
                 iter;
                 ++iter) {
                // Geometry cannot overlap previous geometry at all
                gfx::Rect geometry = iter.geometry_rect();
                EXPECT_TRUE(expect_rect.Contains(geometry));
                EXPECT_TRUE(remaining.Contains(geometry));
                remaining.Subtract(geometry);

                // Sanity check that texture coords are within the texture rect.
                // Skip check for external edges because they do overhang.
                // For internal edges there is an inset of 0.5 texels because the sample
                // points are at the center of the texels. An extra 1/1024 tolerance
                // is allowed for numerical errors.
                // Refer to picture_layer_tiling.cc for detailed analysis.
                const float inset = loose_texel_extent_check_ ? 0 : (0.5f - 1.f / 1024.f);
                gfx::RectF texture_rect = iter.texture_rect();
                if (iter.i())
                    EXPECT_GE(texture_rect.x(), inset);
                if (iter.j())
                    EXPECT_GE(texture_rect.y(), inset);
                if (iter.i() != tiling_->tiling_data()->num_tiles_x() - 1)
                    EXPECT_LE(texture_rect.right(), client_.TileSize().width() - inset);
                if (iter.j() != tiling_->tiling_data()->num_tiles_y() - 1)
                    EXPECT_LE(texture_rect.bottom(), client_.TileSize().height() - inset);
            }

            // The entire rect must be filled by geometry from the tiling.
            EXPECT_TRUE(remaining.IsEmpty());
        }

        void VerifyTilesExactlyCoverRect(float rect_scale, const gfx::Rect& rect)
        {
            VerifyTilesExactlyCoverRect(rect_scale, rect, rect);
        }

        void VerifyTiles(
            float rect_scale,
            const gfx::Rect& rect,
            base::Callback<void(Tile* tile,
                const gfx::Rect& geometry_rect)>
                callback)
        {
            VerifyTiles(tiling_.get(),
                rect_scale,
                rect,
                callback);
        }

        void VerifyTiles(
            PictureLayerTiling* tiling,
            float rect_scale,
            const gfx::Rect& rect,
            base::Callback<void(Tile* tile,
                const gfx::Rect& geometry_rect)>
                callback)
        {
            Region remaining = rect;
            for (PictureLayerTiling::CoverageIterator iter(tiling, rect_scale, rect);
                 iter;
                 ++iter) {
                remaining.Subtract(iter.geometry_rect());
                callback.Run(*iter, iter.geometry_rect());
            }
            EXPECT_TRUE(remaining.IsEmpty());
        }

        void VerifyTilesCoverNonContainedRect(float rect_scale,
            const gfx::Rect& dest_rect)
        {
            float dest_to_contents_scale = tiling_->contents_scale() / rect_scale;
            gfx::Rect clamped_rect = gfx::ScaleToEnclosingRect(
                gfx::Rect(tiling_->tiling_size()), 1.f / dest_to_contents_scale);
            clamped_rect.Intersect(dest_rect);
            VerifyTilesExactlyCoverRect(rect_scale, dest_rect, clamped_rect);
        }

    protected:
        FakePictureLayerTilingClient client_;
        std::unique_ptr<TestablePictureLayerTiling> tiling_;
        bool loose_texel_extent_check_ = false;

    private:
        DISALLOW_COPY_AND_ASSIGN(PictureLayerTilingIteratorTest);
    };

    TEST_F(PictureLayerTilingIteratorTest, ResizeDeletesTiles)
    {
        // Verifies that a resize with invalidation for newly exposed pixels will
        // deletes tiles that intersect that invalidation.
        gfx::Size tile_size(100, 100);
        gfx::Size original_layer_size(10, 10);
        InitializeActive(tile_size, 1.f, original_layer_size);
        SetLiveRectAndVerifyTiles(gfx::Rect(original_layer_size));

        // Tiling only has one tile, since its total size is less than one.
        EXPECT_TRUE(tiling_->TileAt(0, 0));

        // Stop creating tiles so that any invalidations are left as holes.
        gfx::Size new_layer_size(200, 200);
        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreatePartiallyFilled(new_layer_size, gfx::Rect());

        Region invalidation = SubtractRegions(gfx::Rect(tile_size), gfx::Rect(original_layer_size));
        tiling_->SetRasterSourceAndResize(raster_source);
        EXPECT_TRUE(tiling_->TileAt(0, 0));
        tiling_->Invalidate(invalidation);
        EXPECT_FALSE(tiling_->TileAt(0, 0));
    }

    TEST_F(PictureLayerTilingIteratorTest, CreateMissingTilesStaysInsideLiveRect)
    {
        // The tiling has three rows and columns.
        Initialize(gfx::Size(100, 100), 1.f, gfx::Size(250, 250));
        EXPECT_EQ(3, tiling_->TilingDataForTesting().num_tiles_x());
        EXPECT_EQ(3, tiling_->TilingDataForTesting().num_tiles_y());

        // The live tiles rect is at the very edge of the right-most and
        // bottom-most tiles. Their border pixels would still be inside the live
        // tiles rect, but the tiles should not exist just for that.
        int right = tiling_->TilingDataForTesting().TileBounds(2, 2).x();
        int bottom = tiling_->TilingDataForTesting().TileBounds(2, 2).y();

        SetLiveRectAndVerifyTiles(gfx::Rect(right, bottom));
        EXPECT_FALSE(tiling_->TileAt(2, 0));
        EXPECT_FALSE(tiling_->TileAt(2, 1));
        EXPECT_FALSE(tiling_->TileAt(2, 2));
        EXPECT_FALSE(tiling_->TileAt(1, 2));
        EXPECT_FALSE(tiling_->TileAt(0, 2));

        // Verify CreateMissingTilesInLiveTilesRect respects this.
        tiling_->CreateMissingTilesInLiveTilesRect();
        EXPECT_FALSE(tiling_->TileAt(2, 0));
        EXPECT_FALSE(tiling_->TileAt(2, 1));
        EXPECT_FALSE(tiling_->TileAt(2, 2));
        EXPECT_FALSE(tiling_->TileAt(1, 2));
        EXPECT_FALSE(tiling_->TileAt(0, 2));
    }

    TEST_F(PictureLayerTilingIteratorTest, ResizeTilingOverTileBorders)
    {
        // The tiling has four rows and three columns.
        Initialize(gfx::Size(100, 100), 1.f, gfx::Size(250, 350));
        EXPECT_EQ(3, tiling_->TilingDataForTesting().num_tiles_x());
        EXPECT_EQ(4, tiling_->TilingDataForTesting().num_tiles_y());

        // The live tiles rect covers the whole tiling.
        SetLiveRectAndVerifyTiles(gfx::Rect(250, 350));

        // Tiles in the bottom row and right column exist.
        EXPECT_TRUE(tiling_->TileAt(2, 0));
        EXPECT_TRUE(tiling_->TileAt(2, 1));
        EXPECT_TRUE(tiling_->TileAt(2, 2));
        EXPECT_TRUE(tiling_->TileAt(2, 3));
        EXPECT_TRUE(tiling_->TileAt(1, 3));
        EXPECT_TRUE(tiling_->TileAt(0, 3));

        int right = tiling_->TilingDataForTesting().TileBounds(2, 2).x();
        int bottom = tiling_->TilingDataForTesting().TileBounds(2, 3).y();

        // Shrink the tiling so that the last tile row/column is entirely in the
        // border pixels of the interior tiles. That row/column is removed.
        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(gfx::Size(right + 1, bottom + 1));
        tiling_->SetRasterSourceAndResize(raster_source);
        EXPECT_EQ(2, tiling_->TilingDataForTesting().num_tiles_x());
        EXPECT_EQ(3, tiling_->TilingDataForTesting().num_tiles_y());

        // The live tiles rect was clamped to the raster source size.
        EXPECT_EQ(gfx::Rect(right + 1, bottom + 1), tiling_->live_tiles_rect());

        // Since the row/column is gone, the tiles should be gone too.
        EXPECT_FALSE(tiling_->TileAt(2, 0));
        EXPECT_FALSE(tiling_->TileAt(2, 1));
        EXPECT_FALSE(tiling_->TileAt(2, 2));
        EXPECT_FALSE(tiling_->TileAt(2, 3));
        EXPECT_FALSE(tiling_->TileAt(1, 3));
        EXPECT_FALSE(tiling_->TileAt(0, 3));

        // Growing outside the current right/bottom tiles border pixels should create
        // the tiles again, even though the live rect has not changed size.
        raster_source = FakeRasterSource::CreateFilled(gfx::Size(right + 2, bottom + 2));
        tiling_->SetRasterSourceAndResize(raster_source);
        EXPECT_EQ(3, tiling_->TilingDataForTesting().num_tiles_x());
        EXPECT_EQ(4, tiling_->TilingDataForTesting().num_tiles_y());

        // Not changed.
        EXPECT_EQ(gfx::Rect(right + 1, bottom + 1), tiling_->live_tiles_rect());

        // The last row/column tiles are inside the live tiles rect.
        EXPECT_TRUE(gfx::Rect(right + 1, bottom + 1).Intersects(tiling_->TilingDataForTesting().TileBounds(2, 0)));
        EXPECT_TRUE(gfx::Rect(right + 1, bottom + 1).Intersects(tiling_->TilingDataForTesting().TileBounds(0, 3)));

        EXPECT_TRUE(tiling_->TileAt(2, 0));
        EXPECT_TRUE(tiling_->TileAt(2, 1));
        EXPECT_TRUE(tiling_->TileAt(2, 2));
        EXPECT_TRUE(tiling_->TileAt(2, 3));
        EXPECT_TRUE(tiling_->TileAt(1, 3));
        EXPECT_TRUE(tiling_->TileAt(0, 3));
    }

    TEST_F(PictureLayerTilingIteratorTest, ResizeLiveTileRectOverTileBorders)
    {
        // The tiling has three rows and columns.
        Initialize(gfx::Size(100, 100), 1.f, gfx::Size(250, 350));
        EXPECT_EQ(3, tiling_->TilingDataForTesting().num_tiles_x());
        EXPECT_EQ(4, tiling_->TilingDataForTesting().num_tiles_y());

        // The live tiles rect covers the whole tiling.
        SetLiveRectAndVerifyTiles(gfx::Rect(250, 350));

        // Tiles in the bottom row and right column exist.
        EXPECT_TRUE(tiling_->TileAt(2, 0));
        EXPECT_TRUE(tiling_->TileAt(2, 1));
        EXPECT_TRUE(tiling_->TileAt(2, 2));
        EXPECT_TRUE(tiling_->TileAt(2, 3));
        EXPECT_TRUE(tiling_->TileAt(1, 3));
        EXPECT_TRUE(tiling_->TileAt(0, 3));

        // Shrink the live tiles rect to the very edge of the right-most and
        // bottom-most tiles. Their border pixels would still be inside the live
        // tiles rect, but the tiles should not exist just for that.
        int right = tiling_->TilingDataForTesting().TileBounds(2, 3).x();
        int bottom = tiling_->TilingDataForTesting().TileBounds(2, 3).y();

        SetLiveRectAndVerifyTiles(gfx::Rect(right, bottom));
        EXPECT_FALSE(tiling_->TileAt(2, 0));
        EXPECT_FALSE(tiling_->TileAt(2, 1));
        EXPECT_FALSE(tiling_->TileAt(2, 2));
        EXPECT_FALSE(tiling_->TileAt(2, 3));
        EXPECT_FALSE(tiling_->TileAt(1, 3));
        EXPECT_FALSE(tiling_->TileAt(0, 3));

        // Including the bottom row and right column again, should create the tiles.
        SetLiveRectAndVerifyTiles(gfx::Rect(right + 1, bottom + 1));
        EXPECT_TRUE(tiling_->TileAt(2, 0));
        EXPECT_TRUE(tiling_->TileAt(2, 1));
        EXPECT_TRUE(tiling_->TileAt(2, 2));
        EXPECT_TRUE(tiling_->TileAt(2, 3));
        EXPECT_TRUE(tiling_->TileAt(1, 2));
        EXPECT_TRUE(tiling_->TileAt(0, 2));

        // Shrink the live tiles rect to the very edge of the left-most and
        // top-most tiles. Their border pixels would still be inside the live
        // tiles rect, but the tiles should not exist just for that.
        int left = tiling_->TilingDataForTesting().TileBounds(0, 0).right();
        int top = tiling_->TilingDataForTesting().TileBounds(0, 0).bottom();

        SetLiveRectAndVerifyTiles(gfx::Rect(left, top, 250 - left, 350 - top));
        EXPECT_FALSE(tiling_->TileAt(0, 3));
        EXPECT_FALSE(tiling_->TileAt(0, 2));
        EXPECT_FALSE(tiling_->TileAt(0, 1));
        EXPECT_FALSE(tiling_->TileAt(0, 0));
        EXPECT_FALSE(tiling_->TileAt(1, 0));
        EXPECT_FALSE(tiling_->TileAt(2, 0));

        // Including the top row and left column again, should create the tiles.
        SetLiveRectAndVerifyTiles(
            gfx::Rect(left - 1, top - 1, 250 - left, 350 - top));
        EXPECT_TRUE(tiling_->TileAt(0, 3));
        EXPECT_TRUE(tiling_->TileAt(0, 2));
        EXPECT_TRUE(tiling_->TileAt(0, 1));
        EXPECT_TRUE(tiling_->TileAt(0, 0));
        EXPECT_TRUE(tiling_->TileAt(1, 0));
        EXPECT_TRUE(tiling_->TileAt(2, 0));
    }

    TEST_F(PictureLayerTilingIteratorTest, ResizeLiveTileRectOverSameTiles)
    {
        // The tiling has four rows and three columns.
        Initialize(gfx::Size(100, 100), 1.f, gfx::Size(250, 350));
        EXPECT_EQ(3, tiling_->TilingDataForTesting().num_tiles_x());
        EXPECT_EQ(4, tiling_->TilingDataForTesting().num_tiles_y());

        // The live tiles rect covers the whole tiling.
        SetLiveRectAndVerifyTiles(gfx::Rect(250, 350));

        // All tiles exist.
        for (int i = 0; i < 3; ++i) {
            for (int j = 0; j < 4; ++j)
                EXPECT_TRUE(tiling_->TileAt(i, j)) << i << "," << j;
        }

        // Shrink the live tiles rect, but still cover all the tiles.
        SetLiveRectAndVerifyTiles(gfx::Rect(1, 1, 249, 349));

        // All tiles still exist.
        for (int i = 0; i < 3; ++i) {
            for (int j = 0; j < 4; ++j)
                EXPECT_TRUE(tiling_->TileAt(i, j)) << i << "," << j;
        }

        // Grow the live tiles rect, but still cover all the same tiles.
        SetLiveRectAndVerifyTiles(gfx::Rect(0, 0, 250, 350));

        // All tiles still exist.
        for (int i = 0; i < 3; ++i) {
            for (int j = 0; j < 4; ++j)
                EXPECT_TRUE(tiling_->TileAt(i, j)) << i << "," << j;
        }
    }

    TEST_F(PictureLayerTilingIteratorTest, ResizeOverBorderPixelsDeletesTiles)
    {
        // Verifies that a resize with invalidation for newly exposed pixels will
        // deletes tiles that intersect that invalidation.
        gfx::Size tile_size(100, 100);
        gfx::Size original_layer_size(99, 99);
        InitializeActive(tile_size, 1.f, original_layer_size);
        SetLiveRectAndVerifyTiles(gfx::Rect(original_layer_size));

        // Tiling only has one tile, since its total size is less than one.
        EXPECT_TRUE(tiling_->TileAt(0, 0));

        // Stop creating tiles so that any invalidations are left as holes.
        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreatePartiallyFilled(gfx::Size(200, 200), gfx::Rect());
        tiling_->SetRasterSourceAndResize(raster_source);

        Region invalidation = SubtractRegions(gfx::Rect(tile_size), gfx::Rect(original_layer_size));
        EXPECT_TRUE(tiling_->TileAt(0, 0));
        tiling_->Invalidate(invalidation);
        EXPECT_FALSE(tiling_->TileAt(0, 0));

        // The original tile was the same size after resize, but it would include new
        // border pixels.
        EXPECT_EQ(gfx::Rect(original_layer_size),
            tiling_->TilingDataForTesting().TileBounds(0, 0));
    }

    TEST_F(PictureLayerTilingIteratorTest, RemoveOutsideLayerKeepsTiles)
    {
        gfx::Size tile_size(100, 100);
        gfx::Size layer_size(100, 100);
        InitializeActive(tile_size, 1.f, layer_size);
        SetLiveRectAndVerifyTiles(gfx::Rect(layer_size));

        // In all cases here, the tiling should remain with one tile, since the remove
        // region doesn't intersect it.

        bool recreate_tiles = false;
        // Top
        tiling_->RemoveTilesInRegion(gfx::Rect(50, -1, 1, 1), recreate_tiles);
        EXPECT_TRUE(tiling_->TileAt(0, 0));
        // Bottom
        tiling_->RemoveTilesInRegion(gfx::Rect(50, 100, 1, 1), recreate_tiles);
        EXPECT_TRUE(tiling_->TileAt(0, 0));
        // Left
        tiling_->RemoveTilesInRegion(gfx::Rect(-1, 50, 1, 1), recreate_tiles);
        EXPECT_TRUE(tiling_->TileAt(0, 0));
        // Right
        tiling_->RemoveTilesInRegion(gfx::Rect(100, 50, 1, 1), recreate_tiles);
        EXPECT_TRUE(tiling_->TileAt(0, 0));
    }

    TEST_F(PictureLayerTilingIteratorTest, CreateTileJustCoverBorderUp)
    {
        float content_scale = 1.2000000476837158f;
        gfx::Size tile_size(512, 512);
        gfx::Size layer_size(1440, 4560);
        FakePictureLayerTilingClient active_client;

        active_client.SetTileSize(tile_size);
        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(layer_size);
        std::unique_ptr<TestablePictureLayerTiling> active_tiling = TestablePictureLayerTiling::Create(ACTIVE_TREE, content_scale,
            raster_source, &active_client,
            LayerTreeSettings());
        active_tiling->set_resolution(HIGH_RESOLUTION);

        gfx::Rect invalid_rect(0, 750, 220, 100);
        Initialize(tile_size, content_scale, layer_size);
        client_.set_twin_tiling(active_tiling.get());
        client_.set_invalidation(invalid_rect);
        SetLiveRectAndVerifyTiles(gfx::Rect(layer_size));
        // When it creates a tile in pending tree, verify that tiles are invalidated
        // even if only their border pixels intersect the invalidation rect
        EXPECT_TRUE(tiling_->TileAt(0, 1));
        gfx::Rect scaled_invalid_rect = gfx::ScaleToEnclosingRect(invalid_rect, content_scale);
        EXPECT_FALSE(scaled_invalid_rect.Intersects(
            tiling_->TilingDataForTesting().TileBounds(0, 2)));
        EXPECT_TRUE(scaled_invalid_rect.Intersects(
            tiling_->TilingDataForTesting().TileBoundsWithBorder(0, 2)));
        EXPECT_TRUE(tiling_->TileAt(0, 2));

        bool recreate_tiles = false;
        active_tiling->RemoveTilesInRegion(invalid_rect, recreate_tiles);
        // Even though a tile just touch border area of invalid region, verify that
        // RemoveTilesInRegion behaves the same as SetLiveRectAndVerifyTiles with
        // respect to the tiles that it invalidates
        EXPECT_FALSE(active_tiling->TileAt(0, 1));
        EXPECT_FALSE(active_tiling->TileAt(0, 2));
    }

    TEST_F(PictureLayerTilingIteratorTest, LiveTilesExactlyCoverLiveTileRect)
    {
        Initialize(gfx::Size(100, 100), 1.f, gfx::Size(1099, 801));
        SetLiveRectAndVerifyTiles(gfx::Rect(100, 100));
        SetLiveRectAndVerifyTiles(gfx::Rect(101, 99));
        SetLiveRectAndVerifyTiles(gfx::Rect(1099, 1));
        SetLiveRectAndVerifyTiles(gfx::Rect(1, 801));
        SetLiveRectAndVerifyTiles(gfx::Rect(1099, 1));
        SetLiveRectAndVerifyTiles(gfx::Rect(201, 800));
    }

    TEST_F(PictureLayerTilingIteratorTest, IteratorCoversLayerBoundsNoScale)
    {
        Initialize(gfx::Size(100, 100), 1.f, gfx::Size(1099, 801));
        VerifyTilesExactlyCoverRect(1, gfx::Rect());
        VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1099, 801));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(52, 83, 789, 412));

        // With borders, a size of 3x3 = 1 pixel of content.
        Initialize(gfx::Size(3, 3), 1.f, gfx::Size(10, 10));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1, 1));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 2, 2));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(1, 1, 2, 2));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(3, 2, 5, 2));
    }

    TEST_F(PictureLayerTilingIteratorTest, IteratorCoversLayerBoundsTilingScale)
    {
        Initialize(gfx::Size(200, 100), 2.0f, gfx::Size(1005, 2010));
        VerifyTilesExactlyCoverRect(2, gfx::Rect());
        VerifyTilesExactlyCoverRect(2, gfx::Rect(0, 0, 2010, 4020));
        VerifyTilesExactlyCoverRect(2, gfx::Rect(100, 224, 1024, 762));

        Initialize(gfx::Size(3, 3), 2.0f, gfx::Size(10, 10));
        VerifyTilesExactlyCoverRect(2, gfx::Rect());
        VerifyTilesExactlyCoverRect(2, gfx::Rect(0, 0, 1, 1));
        VerifyTilesExactlyCoverRect(2, gfx::Rect(0, 0, 2, 2));
        VerifyTilesExactlyCoverRect(2, gfx::Rect(1, 1, 2, 2));
        VerifyTilesExactlyCoverRect(2, gfx::Rect(3, 2, 5, 2));

        Initialize(gfx::Size(100, 200), 0.5f, gfx::Size(1005, 2010));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1005, 2010));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(50, 112, 512, 381));

        Initialize(gfx::Size(150, 250), 0.37f, gfx::Size(1005, 2010));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1005, 2010));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(50, 112, 512, 381));

        Initialize(gfx::Size(312, 123), 0.01f, gfx::Size(1005, 2010));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(0, 0, 1005, 2010));
        VerifyTilesExactlyCoverRect(1, gfx::Rect(50, 112, 512, 381));
    }

    TEST_F(PictureLayerTilingIteratorTest, IteratorCoversLayerBoundsBothScale)
    {
        Initialize(gfx::Size(50, 50), 4.0f, gfx::Size(800, 600));
        VerifyTilesExactlyCoverRect(4.0f, gfx::Rect());
        VerifyTilesExactlyCoverRect(4.0f, gfx::Rect(0, 0, 3200, 2400));
        VerifyTilesExactlyCoverRect(4.0f, gfx::Rect(1024, 730, 506, 364));

        float scale = 6.7f;
        gfx::Size bounds(800, 600);
        gfx::Rect full_rect(gfx::ScaleToCeiledSize(bounds, scale));
        Initialize(gfx::Size(256, 512), 5.2f, bounds);
        VerifyTilesExactlyCoverRect(scale, full_rect);
        VerifyTilesExactlyCoverRect(scale, gfx::Rect(2014, 1579, 867, 1033));
    }

    TEST_F(PictureLayerTilingIteratorTest, IteratorEmptyRect)
    {
        Initialize(gfx::Size(100, 100), 1.0f, gfx::Size(800, 600));

        gfx::Rect empty;
        PictureLayerTiling::CoverageIterator iter(tiling_.get(), 1.0f, empty);
        EXPECT_FALSE(iter);
    }

    TEST_F(PictureLayerTilingIteratorTest, NonIntersectingRect)
    {
        Initialize(gfx::Size(100, 100), 1.0f, gfx::Size(800, 600));
        gfx::Rect non_intersecting(1000, 1000, 50, 50);
        PictureLayerTiling::CoverageIterator iter(tiling_.get(), 1, non_intersecting);
        EXPECT_FALSE(iter);
    }

    TEST_F(PictureLayerTilingIteratorTest, LayerEdgeTextureCoordinates)
    {
        Initialize(gfx::Size(300, 300), 1.0f, gfx::Size(256, 256));
        // All of these sizes are 256x256, scaled and ceiled.
        VerifyTilesExactlyCoverRect(1.0f, gfx::Rect(0, 0, 256, 256));
        VerifyTilesExactlyCoverRect(1.2f, gfx::Rect(0, 0, 308, 308));
    }

    TEST_F(PictureLayerTilingIteratorTest, NonContainedDestRect)
    {
        Initialize(gfx::Size(100, 100), 1.0f, gfx::Size(400, 400));

        // Too large in all dimensions
        VerifyTilesCoverNonContainedRect(1.0f, gfx::Rect(-1000, -1000, 2000, 2000));
        VerifyTilesCoverNonContainedRect(1.5f, gfx::Rect(-1000, -1000, 2000, 2000));

        // Partially covering content, but too large
        VerifyTilesCoverNonContainedRect(1.0f, gfx::Rect(-1000, 100, 2000, 100));
        VerifyTilesCoverNonContainedRect(1.5f, gfx::Rect(-1000, 100, 2000, 100));
    }

    static void TileExists(bool exists, Tile* tile,
        const gfx::Rect& geometry_rect)
    {
        EXPECT_EQ(exists, tile != NULL) << geometry_rect.ToString();
    }

    TEST_F(PictureLayerTilingIteratorTest, TilesExist)
    {
        gfx::Size layer_bounds(1099, 801);
        Initialize(gfx::Size(100, 100), 1.f, layer_bounds);
        VerifyTilesExactlyCoverRect(1.f, gfx::Rect(layer_bounds));
        VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));

        tiling_->ComputeTilePriorityRects(
            gfx::Rect(layer_bounds), // visible rect
            gfx::Rect(layer_bounds), // skewport
            gfx::Rect(layer_bounds), // soon border rect
            gfx::Rect(layer_bounds), // eventually rect
            1.f, // current contents scale
            Occlusion());
        VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, true));

        // Make the viewport rect empty. All tiles are killed and become zombies.
        tiling_->ComputeTilePriorityRects(gfx::Rect(), gfx::Rect(), gfx::Rect(),
            gfx::Rect(), 1.f, Occlusion());
        VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));
    }

    TEST_F(PictureLayerTilingIteratorTest, TilesExistGiantViewport)
    {
        gfx::Size layer_bounds(1099, 801);
        Initialize(gfx::Size(100, 100), 1.f, layer_bounds);
        VerifyTilesExactlyCoverRect(1.f, gfx::Rect(layer_bounds));
        VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));

        gfx::Rect giant_rect(-10000000, -10000000, 1000000000, 1000000000);

        tiling_->ComputeTilePriorityRects(
            gfx::Rect(layer_bounds), // visible rect
            gfx::Rect(layer_bounds), // skewport
            gfx::Rect(layer_bounds), // soon border rect
            gfx::Rect(layer_bounds), // eventually rect
            1.f, // current contents scale
            Occlusion());
        VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, true));

        // If the visible content rect is huge, we should still have live tiles.
        tiling_->ComputeTilePriorityRects(giant_rect, giant_rect, giant_rect,
            giant_rect, 1.f, Occlusion());
        VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, true));
    }

    TEST_F(PictureLayerTilingIteratorTest, TilesExistOutsideViewport)
    {
        gfx::Size layer_bounds(1099, 801);
        Initialize(gfx::Size(100, 100), 1.f, layer_bounds);
        VerifyTilesExactlyCoverRect(1.f, gfx::Rect(layer_bounds));
        VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));

        // This rect does not intersect with the layer, as the layer is outside the
        // viewport.
        gfx::Rect viewport_rect(1100, 0, 1000, 1000);
        EXPECT_FALSE(viewport_rect.Intersects(gfx::Rect(layer_bounds)));

        LayerTreeSettings settings;
        gfx::Rect eventually_rect = viewport_rect;
        eventually_rect.Inset(-settings.tiling_interest_area_padding,
            -settings.tiling_interest_area_padding);
        tiling_->ComputeTilePriorityRects(viewport_rect, viewport_rect, viewport_rect,
            eventually_rect, 1.f, Occlusion());
        VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, true));
    }

    static void TilesIntersectingRectExist(const gfx::Rect& rect,
        bool intersect_exists,
        Tile* tile,
        const gfx::Rect& geometry_rect)
    {
        bool intersects = rect.Intersects(geometry_rect);
        bool expected_exists = intersect_exists ? intersects : !intersects;
        EXPECT_EQ(expected_exists, tile != NULL)
            << "Rects intersecting " << rect.ToString() << " should exist. "
            << "Current tile rect is " << geometry_rect.ToString();
    }

    TEST_F(PictureLayerTilingIteratorTest,
        TilesExistLargeViewportAndLayerWithSmallVisibleArea)
    {
        gfx::Size layer_bounds(10000, 10000);
        client_.SetTileSize(gfx::Size(100, 100));
        LayerTreeSettings settings;
        settings.tiling_interest_area_padding = 1;

        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(layer_bounds);
        tiling_ = TestablePictureLayerTiling::Create(PENDING_TREE, 1.f, raster_source,
            &client_, settings);
        tiling_->set_resolution(HIGH_RESOLUTION);
        VerifyTilesExactlyCoverRect(1.f, gfx::Rect(layer_bounds));
        VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));

        gfx::Rect visible_rect(8000, 8000, 50, 50);

        tiling_->ComputeTilePriorityRects(visible_rect, // visible rect
            visible_rect, // skewport
            visible_rect, // soon border rect
            visible_rect, // eventually rect
            1.f, // current contents scale
            Occlusion());
        VerifyTiles(1.f,
            gfx::Rect(layer_bounds),
            base::Bind(&TilesIntersectingRectExist, visible_rect, true));
    }

    TEST(ComputeTilePriorityRectsTest, VisibleTiles)
    {
        // The TilePriority of visible tiles should have zero distance_to_visible
        // and time_to_visible.
        FakePictureLayerTilingClient client;

        gfx::Size device_viewport(800, 600);
        gfx::Size last_layer_bounds(200, 200);
        gfx::Size current_layer_bounds(200, 200);
        float current_layer_contents_scale = 1.f;
        gfx::Transform current_screen_transform;

        gfx::Rect viewport_in_layer_space = ViewportInLayerSpace(
            current_screen_transform, device_viewport);

        client.SetTileSize(gfx::Size(100, 100));

        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(current_layer_bounds);
        std::unique_ptr<TestablePictureLayerTiling> tiling = TestablePictureLayerTiling::Create(ACTIVE_TREE, 1.0f, raster_source,
            &client, LayerTreeSettings());
        tiling->set_resolution(HIGH_RESOLUTION);

        LayerTreeSettings settings;
        gfx::Rect eventually_rect = viewport_in_layer_space;
        eventually_rect.Inset(-settings.tiling_interest_area_padding,
            -settings.tiling_interest_area_padding);
        tiling->ComputeTilePriorityRects(
            viewport_in_layer_space, viewport_in_layer_space, viewport_in_layer_space,
            eventually_rect, current_layer_contents_scale, Occlusion());
        auto prioritized_tiles = tiling->UpdateAndGetAllPrioritizedTilesForTesting();

        ASSERT_TRUE(tiling->TileAt(0, 0));
        ASSERT_TRUE(tiling->TileAt(0, 1));
        ASSERT_TRUE(tiling->TileAt(1, 0));
        ASSERT_TRUE(tiling->TileAt(1, 1));

        TilePriority priority = prioritized_tiles[tiling->TileAt(0, 0)].priority();
        EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
        EXPECT_FLOAT_EQ(TilePriority::NOW, priority.priority_bin);

        priority = prioritized_tiles[tiling->TileAt(0, 1)].priority();
        EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
        EXPECT_FLOAT_EQ(TilePriority::NOW, priority.priority_bin);

        priority = prioritized_tiles[tiling->TileAt(1, 0)].priority();
        EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
        EXPECT_FLOAT_EQ(TilePriority::NOW, priority.priority_bin);

        priority = prioritized_tiles[tiling->TileAt(1, 1)].priority();
        EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
        EXPECT_FLOAT_EQ(TilePriority::NOW, priority.priority_bin);
    }

    TEST(ComputeTilePriorityRectsTest, OffscreenTiles)
    {
        // The TilePriority of offscreen tiles (without movement) should have nonzero
        // distance_to_visible and infinite time_to_visible.
        FakePictureLayerTilingClient client;

        gfx::Size device_viewport(800, 600);
        gfx::Size last_layer_bounds(200, 200);
        gfx::Size current_layer_bounds(200, 200);
        float current_layer_contents_scale = 1.f;
        gfx::Transform last_screen_transform;
        gfx::Transform current_screen_transform;

        current_screen_transform.Translate(850, 0);
        last_screen_transform = current_screen_transform;

        gfx::Rect viewport_in_layer_space = ViewportInLayerSpace(
            current_screen_transform, device_viewport);

        client.SetTileSize(gfx::Size(100, 100));

        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(current_layer_bounds);
        std::unique_ptr<TestablePictureLayerTiling> tiling = TestablePictureLayerTiling::Create(ACTIVE_TREE, 1.0f, raster_source,
            &client, LayerTreeSettings());
        tiling->set_resolution(HIGH_RESOLUTION);

        LayerTreeSettings settings;
        gfx::Rect eventually_rect = viewport_in_layer_space;
        eventually_rect.Inset(-settings.tiling_interest_area_padding,
            -settings.tiling_interest_area_padding);
        tiling->ComputeTilePriorityRects(
            viewport_in_layer_space, viewport_in_layer_space, viewport_in_layer_space,
            eventually_rect, current_layer_contents_scale, Occlusion());
        auto prioritized_tiles = tiling->UpdateAndGetAllPrioritizedTilesForTesting();

        ASSERT_TRUE(tiling->TileAt(0, 0));
        ASSERT_TRUE(tiling->TileAt(0, 1));
        ASSERT_TRUE(tiling->TileAt(1, 0));
        ASSERT_TRUE(tiling->TileAt(1, 1));

        TilePriority priority = prioritized_tiles[tiling->TileAt(0, 0)].priority();
        EXPECT_GT(priority.distance_to_visible, 0.f);
        EXPECT_NE(TilePriority::NOW, priority.priority_bin);

        priority = prioritized_tiles[tiling->TileAt(0, 1)].priority();
        EXPECT_GT(priority.distance_to_visible, 0.f);
        EXPECT_NE(TilePriority::NOW, priority.priority_bin);

        priority = prioritized_tiles[tiling->TileAt(1, 0)].priority();
        EXPECT_GT(priority.distance_to_visible, 0.f);
        EXPECT_NE(TilePriority::NOW, priority.priority_bin);

        priority = prioritized_tiles[tiling->TileAt(1, 1)].priority();
        EXPECT_GT(priority.distance_to_visible, 0.f);
        EXPECT_NE(TilePriority::NOW, priority.priority_bin);

        // Furthermore, in this scenario tiles on the right hand side should have a
        // larger distance to visible.
        TilePriority left = prioritized_tiles[tiling->TileAt(0, 0)].priority();
        TilePriority right = prioritized_tiles[tiling->TileAt(1, 0)].priority();
        EXPECT_GT(right.distance_to_visible, left.distance_to_visible);

        left = prioritized_tiles[tiling->TileAt(0, 1)].priority();
        right = prioritized_tiles[tiling->TileAt(1, 1)].priority();
        EXPECT_GT(right.distance_to_visible, left.distance_to_visible);
    }

    TEST(ComputeTilePriorityRectsTest, PartiallyOffscreenLayer)
    {
        // Sanity check that a layer with some tiles visible and others offscreen has
        // correct TilePriorities for each tile.
        FakePictureLayerTilingClient client;

        gfx::Size device_viewport(800, 600);
        gfx::Size last_layer_bounds(200, 200);
        gfx::Size current_layer_bounds(200, 200);
        float current_layer_contents_scale = 1.f;
        gfx::Transform last_screen_transform;
        gfx::Transform current_screen_transform;

        current_screen_transform.Translate(705, 505);
        last_screen_transform = current_screen_transform;

        gfx::Rect viewport_in_layer_space = ViewportInLayerSpace(
            current_screen_transform, device_viewport);

        client.SetTileSize(gfx::Size(100, 100));

        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(current_layer_bounds);
        std::unique_ptr<TestablePictureLayerTiling> tiling = TestablePictureLayerTiling::Create(ACTIVE_TREE, 1.0f, raster_source,
            &client, LayerTreeSettings());
        tiling->set_resolution(HIGH_RESOLUTION);

        LayerTreeSettings settings;
        gfx::Rect eventually_rect = viewport_in_layer_space;
        eventually_rect.Inset(-settings.tiling_interest_area_padding,
            -settings.tiling_interest_area_padding);
        tiling->ComputeTilePriorityRects(
            viewport_in_layer_space, viewport_in_layer_space, viewport_in_layer_space,
            eventually_rect, current_layer_contents_scale, Occlusion());
        auto prioritized_tiles = tiling->UpdateAndGetAllPrioritizedTilesForTesting();

        ASSERT_TRUE(tiling->TileAt(0, 0));
        ASSERT_TRUE(tiling->TileAt(0, 1));
        ASSERT_TRUE(tiling->TileAt(1, 0));
        ASSERT_TRUE(tiling->TileAt(1, 1));

        TilePriority priority = prioritized_tiles[tiling->TileAt(0, 0)].priority();
        EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
        EXPECT_FLOAT_EQ(TilePriority::NOW, priority.priority_bin);

        priority = prioritized_tiles[tiling->TileAt(0, 1)].priority();
        EXPECT_GT(priority.distance_to_visible, 0.f);
        EXPECT_NE(TilePriority::NOW, priority.priority_bin);

        priority = prioritized_tiles[tiling->TileAt(1, 0)].priority();
        EXPECT_GT(priority.distance_to_visible, 0.f);
        EXPECT_NE(TilePriority::NOW, priority.priority_bin);

        priority = prioritized_tiles[tiling->TileAt(1, 1)].priority();
        EXPECT_GT(priority.distance_to_visible, 0.f);
        EXPECT_NE(TilePriority::NOW, priority.priority_bin);
    }

    TEST(PictureLayerTilingTest, RecycledTilesClearedOnReset)
    {
        FakePictureLayerTilingClient active_client;
        active_client.SetTileSize(gfx::Size(100, 100));

        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(gfx::Size(100, 100));
        std::unique_ptr<TestablePictureLayerTiling> active_tiling = TestablePictureLayerTiling::Create(ACTIVE_TREE, 1.0f, raster_source,
            &active_client, LayerTreeSettings());
        active_tiling->set_resolution(HIGH_RESOLUTION);
        // Create all tiles on this tiling.
        gfx::Rect visible_rect = gfx::Rect(0, 0, 100, 100);
        active_tiling->ComputeTilePriorityRects(
            visible_rect, visible_rect, visible_rect, visible_rect, 1.f, Occlusion());

        FakePictureLayerTilingClient recycle_client;
        recycle_client.SetTileSize(gfx::Size(100, 100));
        recycle_client.set_twin_tiling(active_tiling.get());

        LayerTreeSettings settings;

        raster_source = FakeRasterSource::CreateFilled(gfx::Size(100, 100));
        std::unique_ptr<TestablePictureLayerTiling> recycle_tiling = TestablePictureLayerTiling::Create(PENDING_TREE, 1.0f, raster_source,
            &recycle_client, settings);
        recycle_tiling->set_resolution(HIGH_RESOLUTION);

        // Create all tiles on the recycle tiling.
        recycle_tiling->ComputeTilePriorityRects(visible_rect, visible_rect,
            visible_rect, visible_rect, 1.0f,
            Occlusion());

        // Set the second tiling as recycled.
        active_client.set_twin_tiling(NULL);
        recycle_client.set_twin_tiling(NULL);

        EXPECT_TRUE(active_tiling->TileAt(0, 0));
        EXPECT_FALSE(recycle_tiling->TileAt(0, 0));

        // Reset the active tiling. The recycle tiles should be released too.
        active_tiling->Reset();
        EXPECT_FALSE(active_tiling->TileAt(0, 0));
        EXPECT_FALSE(recycle_tiling->TileAt(0, 0));
    }

    TEST(PictureLayerTilingTest, EdgeCaseTileNowAndRequired)
    {
        FakePictureLayerTilingClient pending_client;
        pending_client.SetTileSize(gfx::Size(100, 100));

        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(gfx::Size(500, 500));
        std::unique_ptr<TestablePictureLayerTiling> pending_tiling = TestablePictureLayerTiling::Create(PENDING_TREE, 1.0f, raster_source,
            &pending_client, LayerTreeSettings());
        pending_tiling->set_resolution(HIGH_RESOLUTION);
        pending_tiling->set_can_require_tiles_for_activation(true);

        // The tile at (1, 0) should be touching the visible rect, but not
        // intersecting it.
        gfx::Rect visible_rect = gfx::Rect(0, 0, 99, 99);
        gfx::Rect eventually_rect = gfx::Rect(0, 0, 500, 500);
        pending_tiling->ComputeTilePriorityRects(visible_rect, visible_rect,
            visible_rect, eventually_rect, 1.f,
            Occlusion());

        Tile* tile = pending_tiling->TileAt(1, 0);
        EXPECT_NE(pending_tiling->visible_rect_type(),
            pending_tiling->ComputePriorityRectTypeForTile(tile));
        EXPECT_FALSE(pending_tiling->IsTileRequiredForActivation(tile));
        EXPECT_TRUE(tile->content_rect().Intersects(visible_rect));
        EXPECT_FALSE(pending_tiling->tiling_data()
                         ->TileBounds(tile->tiling_i_index(), tile->tiling_j_index())
                         .Intersects(visible_rect));

        // Now the tile at (1, 0) should be intersecting the visible rect.
        visible_rect = gfx::Rect(0, 0, 100, 100);
        pending_tiling->ComputeTilePriorityRects(visible_rect, visible_rect,
            visible_rect, eventually_rect, 1.f,
            Occlusion());
        EXPECT_EQ(pending_tiling->visible_rect_type(),
            pending_tiling->ComputePriorityRectTypeForTile(tile));
        EXPECT_TRUE(pending_tiling->IsTileRequiredForActivation(tile));
        EXPECT_TRUE(tile->content_rect().Intersects(visible_rect));
        EXPECT_TRUE(pending_tiling->tiling_data()
                        ->TileBounds(tile->tiling_i_index(), tile->tiling_j_index())
                        .Intersects(visible_rect));
    }

    TEST_F(PictureLayerTilingIteratorTest, ResizeTilesAndUpdateToCurrent)
    {
        // The tiling has four rows and three columns.
        Initialize(gfx::Size(150, 100), 1.f, gfx::Size(250, 150));
        tiling_->CreateAllTilesForTesting();
        EXPECT_EQ(150, tiling_->TilingDataForTesting().max_texture_size().width());
        EXPECT_EQ(100, tiling_->TilingDataForTesting().max_texture_size().height());
        EXPECT_EQ(4u, tiling_->AllTilesForTesting().size());

        client_.SetTileSize(gfx::Size(250, 200));

        // Tile size in the tiling should still be 150x100.
        EXPECT_EQ(150, tiling_->TilingDataForTesting().max_texture_size().width());
        EXPECT_EQ(100, tiling_->TilingDataForTesting().max_texture_size().height());

        // The layer's size isn't changed, but the tile size was.
        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(gfx::Size(250, 150));
        tiling_->SetRasterSourceAndResize(raster_source);

        // Tile size in the tiling should be resized to 250x200.
        EXPECT_EQ(250, tiling_->TilingDataForTesting().max_texture_size().width());
        EXPECT_EQ(200, tiling_->TilingDataForTesting().max_texture_size().height());
        EXPECT_EQ(0u, tiling_->AllTilesForTesting().size());
    }

    // This test runs into floating point issues because of big numbers.
    TEST_F(PictureLayerTilingIteratorTest, GiantRect)
    {
        loose_texel_extent_check_ = true;

        gfx::Size tile_size(256, 256);
        gfx::Size layer_size(33554432, 33554432);
        float contents_scale = 1.f;

        client_.SetTileSize(tile_size);
        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateEmpty(layer_size);
        tiling_ = TestablePictureLayerTiling::Create(PENDING_TREE, contents_scale,
            raster_source, &client_,
            LayerTreeSettings());

        gfx::Rect content_rect(25554432, 25554432, 950, 860);
        VerifyTilesExactlyCoverRect(contents_scale, content_rect);
    }

    TEST_F(PictureLayerTilingIteratorTest, QuadShouldNotUseLastHalfTexel)
    {
        Initialize(gfx::Size(100, 100), 1.f, gfx::Size(198, 198));
        // Creates a situation that tile bounds get rounded up by almost 1px in the
        // dest space. This test verifies that even in such situation the coverage
        // iterator won't generate a texture rect that can potentially get clamped.
        VerifyTilesExactlyCoverRect(1.000005f, gfx::Rect(199, 199));
    }

    static void TileHasGeometryRect(const gfx::Rect& expected_rect,
        Tile* tile,
        const gfx::Rect& geometry_rect)
    {
        EXPECT_EQ(expected_rect, geometry_rect);
    }

    TEST_F(PictureLayerTilingIteratorTest, UseLeastTilesToCover)
    {
        // This test verifies that when a dest pixel can be covered by more than
        // one tiles, least number of tiles gets emitted.
        Initialize(gfx::Size(100, 100), 1.f, gfx::Size(1000, 1000));
        gfx::RectF overlaped = gfx::ScaleRect(gfx::RectF(198.f, 198.f, 1.f, 1.f), 1.f / 2.f);
        ASSERT_TRUE(tiling_->tiling_data()->TexelExtent(0, 0).Contains(overlaped));
        ASSERT_TRUE(tiling_->tiling_data()->TexelExtent(1, 0).Contains(overlaped));
        ASSERT_TRUE(tiling_->tiling_data()->TexelExtent(0, 1).Contains(overlaped));
        ASSERT_TRUE(tiling_->tiling_data()->TexelExtent(1, 1).Contains(overlaped));
        VerifyTilesExactlyCoverRect(2.f, gfx::Rect(199, 199));
        VerifyTiles(2.f, gfx::Rect(199, 199),
            base::Bind(&TileHasGeometryRect, gfx::Rect(199, 199)));
    }

    TEST_F(PictureLayerTilingIteratorTest, UseLeastTilesToCover2)
    {
        // Similar to above test, but with an internal tile.
        Initialize(gfx::Size(100, 100), 1.f, gfx::Size(1000, 1000));
        gfx::RectF overlaped = gfx::ScaleRect(gfx::RectF(197.f, 393.f, 1.f, 1.f), 1.f / 2.f);
        ASSERT_TRUE(tiling_->tiling_data()->TexelExtent(0, 1).Contains(overlaped));
        ASSERT_TRUE(tiling_->tiling_data()->TexelExtent(1, 1).Contains(overlaped));
        ASSERT_TRUE(tiling_->tiling_data()->TexelExtent(0, 2).Contains(overlaped));
        ASSERT_TRUE(tiling_->tiling_data()->TexelExtent(1, 2).Contains(overlaped));
        gfx::Rect dest_rect(197, 393, 198, 198);
        VerifyTilesExactlyCoverRect(2.f, dest_rect);
        VerifyTiles(2.f, dest_rect, base::Bind(&TileHasGeometryRect, dest_rect));
    }

    TEST_F(PictureLayerTilingIteratorTest, TightCover)
    {
        // This test verifies that the whole dest rect is still fully covered when
        // numerical condition is tight.
        // In this test, the right edge of tile #37 almost (but failed to) covered
        // grid line x = 9654. Tile #38 needs to reach hard to x = 9653 to make up
        // for this.
        Initialize(gfx::Size(256, 256), 1.f, gfx::Size(10000, 1));
        float dest_scale = 16778082.f / 16777216.f; // 0b1.00000000 00000011 01100010
        VerifyTilesExactlyCoverRect(dest_scale, gfx::Rect(10001, 2));
    }

    TEST_F(PictureLayerTilingIteratorTest, TightCover2)
    {
        // In this test, the left edge of tile #38 almost (but failed to) covered
        // grid line x = 9653. Tile #37 needs to reach hard to x = 9654 to make up
        // for this.
        Initialize(gfx::Size(256, 256), 1.f, gfx::Size(10000, 1));
        float dest_scale = 16778088.f / 16777216.f; // 0b1.00000000 00000011 01101000
        VerifyTilesExactlyCoverRect(dest_scale, gfx::Rect(10001, 2));
    }

    TEST_F(PictureLayerTilingIteratorTest, TilesStoreTilings)
    {
        gfx::Size bounds(200, 200);
        Initialize(gfx::Size(100, 100), 1.f, bounds);
        SetLiveRectAndVerifyTiles(gfx::Rect(bounds));

        // Get all tiles and ensure they are associated with |tiling_|.
        std::vector<Tile*> tiles = tiling_->AllTilesForTesting();
        EXPECT_TRUE(tiles.size());
        for (const auto* tile : tiles) {
            EXPECT_EQ(tile->tiling(), tiling_.get());
        }

        // Create an active tiling, transfer tiles to that tiling, and ensure that
        // the tiles have their tiling updated.
        scoped_refptr<FakeRasterSource> raster_source = FakeRasterSource::CreateFilled(bounds);
        auto active_tiling = TestablePictureLayerTiling::Create(
            ACTIVE_TREE, 1.f, raster_source, &client_, LayerTreeSettings());
        active_tiling->set_resolution(HIGH_RESOLUTION);

        active_tiling->TakeTilesAndPropertiesFrom(tiling_.get(),
            Region(gfx::Rect(bounds)));
        for (const auto* tile : tiles) {
            EXPECT_EQ(tile->tiling(), active_tiling.get());
        }
    }

} // namespace
} // namespace cc
